This invention relates generally to improvements relating to hygiene and medical products. The invention is particularly suitable for personal hygiene projects such as ostomy bags, but the invention is not limited exclusively to such use.
The conventional approach to the manufacture of ostomy bags has been to use a material which is impermeable to gas, in order to prevent unpleasant odours from leaking by seepage of gas through the bag wall. Such odours are present in flatus, and are also produced by bacterial action in decomposing faecal matter. The human nose is extremely sensitive to such odours (usually caused by hydrogen sulphide gas), and it is critical for customer acceptance that no unpleasant odours be allowed to escape while the bag is worn. Typically, a vent with a filter is provided through which filtered gas can escape to avoid the build up of gas within the bag. However, the effect of the filter will be wasted if even small amounts of odour-carrying gas are permitted to seep through the bag walls.
In order to achieve the necessary gas-impermeability, a gas-impermeable barrier layer is usually included in the plastics laminate constituting the bag wall material. The most common, and effective, barrier material is polyvinylidene chloride (PVDC). However, PVDC is expensive, and is a difficult material to handle. There are growing safety and environmental concerns regarding the safe disposal of PVDC, particularly by incineration. Moreover, PVDC has a highly crystalline structure, which makes the laminate "noisy" in the sense that the material will crackle or rustle when it moves, or is bent, or slides under a person's clothing. Such noises can be embarrassing for the wearer of the bag.
The present invention has been devised bearing such problems in mind.
In a first aspect, the invention provides a container for carrying or collecting odorous material, wherein the container carries or contains microencapsulated malodour counteractant material.
In a closely-related second aspect, the invention provides an ostomy bag carrying or containing microencapsulated malodour counteractant material.
The invention can alleviate the need to provide a gas-impermeable barrier layer (e.g. of PVDC) in the wall material of the container. Instead, wall material can be used which does allow permeation of gas through the wall. The malodour counteractant is released and is able to counter the unpleasant odour within the bag. Therefore, any gas which does permeate through the container wall will not have an unpleasant odour.
Microencapsulation is a known technique in which a very small quantity of a material is encapsulated within a layer, or skin of encapsulant material. In the present case encapsulation traps the malodour counteractant material, thereby preserving its state and preventing dispersal or substantial decay of its malodour counteractant properties. The encapsulant is such that it is able to release the encapsulated material, for example, by mechanical rupture, temperature dependent release, or moisture-activated release. This can provide controlled, progressive release of the malodour counteractant to provide continued odour suppression.
Microencapsulation has been used in the past to provide so-called "scratch and sniff" smells. Small quantities of a fragrance are encapsulated within an encapsulant material, usually gelatin based, which is then applied to card or paper. When the microencapsulated material is scratched or rubbed, the gelatin skin ruptures, releasing the fragrance.
The microencapsulated malodour counteractant may, for example, be carried on an interior face of a wall of the bag or container. Preferably, the microencapsulated material is carried on the faces of a plurality of walls, more preferably on the interior faces of all of the bag walls.
In the case of a container or bag which has walls welded together along one or more seams, the microencapsulated material may be carried over most of the interior face of the bag wall except the region of the weld. The microencapsulated material might otherwise interfere with the weld around the periphery.
In addition to, or as an alternative to, the microencapsulated material being carried on the wall of the bag or container, the microencapsulated material may be carried on an article placed within the bag or container. For example, the microencapsulated material may be carried on an absorbent or a superabsorbent article, such as that described in GB-A-2,301,350.
In a closely-related aspect, the invention provides a product for insertion in an ostomy bag, the product carrying microencapsulated malodour counteractant material.
In a further closely-related aspect, the invention provides a product comprising super-absorbent material and microencapsulated malodour counteractant material.
In a further closely-related aspect, the invention provides a medical or hygiene product carrying or containing a microencapsulated active material such that, in use, the active material is releasable from the microencapsulated state.
The term "active material" is intended to cover any material providing a medical or hygiene function, in use. For example, such materials include malodour counteractants, medicaments, and disinfectants.
In a closely related aspect, the invention provides a container for containing or collecting unpleasantly odorous material, the container having at least one wall made of material which is at least partly permeable to gas, the container carrying or containing a malodour counteractant material to counter the unpleasant odour of gas leaking through the container wall.
Preferably, the container further comprises a vent providing a main gas escape path for gas.
The term "at least partly permeable" is intended to refer to the material being such that at least some gas can leak through the wall in sufficient quantity to produce a detectable unpleasant odour outside the container, were it not for the presence of the malodour counteractant.
Preferably, the container is an ostomy bag.
In a closely-related further aspect, the invention provides a method of applying a malodour counteractant to a product for ostomy use, the method comprising applying the malodour counteractant in a microencapsulated state.
In a yet further closely related aspect, the invention provides a method of applying an active material to a medical or hygiene product, the method comprising applying the active material in a microencapsulated state.
In the above methods, the microencapsulated material may be solution coated onto the product, or it may be "printed" by any suitable printing technique, such as silk screen printing, tampo-offset printing, or ink-jet printing.